The present invention relates to a method and apparatus for filling bottles or similar containers with liquid material using a filling element that has a liquid flow valve.
A method and associated apparatus of this general type for dispensing a liquid, especially carbonated, material under counterpressure into bottles or similar containers are known (EP-A-0 231 137). Also proposed in this known state of the art is the use of return gas from the return gas channel of the filling machine to reduce the consumption of inert gas or CO.sub.2 gas in the preliminary pressurizing phase for a rinsing and partial pre-pressurizing of the respective container. However, with this known method and apparatus, when return gas is used the desired quality and ability to store the product, especially with a material that is sensitive or easily perishable, cannot be achieved with an adequate reliability, in particular due to the possible existence of bacteria in the return gas of the return gas channel.
In principle, it is also known from U.S. Pat. No. 5,031,673, Clusserath, to treat the respective container with a sterilization medium prior to the preliminary pressurizing stage, whereby however this treatment serves exclusively for dispensing the liquid material in an aseptic or sterile manner, and for this purpose the respective container is accommodated in a closable bell without being in a sealing position with the filling element; initially, the interior of the bell is acted upon by the sterilization medium and then during the filling process is, among others, acted upon by the pressure of an inert gas or with sterile air. Due to the volume of the bell, a disadvantageously high consumption of inert gas or sterile air results.
It is therefore an object of the present invention to improve a method and apparatus of the aforementioned general type in such a way that while maintaining the advantage of being able to reduce the consumption of inert gas, a high quality and long shelf life of the dispensed filling material can be achieved even where the material is sensitive.